I purchased this new last month to use in a rudderless speedboat that uses differential power to steer the boat.

The problem I had is that with the Throttle at full down and the steering centered the mixer was putting out a 25% signal to each ESC. This is normal operation for a 50 / 50 % mixer. 50 % of 0 = 0, 50 % of 50 = 25.
0 + 25 = 25. When power was applied each ESC said NO because the mixer was not sending a 0 % power signal to each ESC.

I needed a connector that mates with my transmitter for the mechanical mixer I built that works in the boat. Guess where I found one?